Bobbin



G. CURTIS April 6, 1954 BOBBIN 2 Sheefcs-Sheet 1 Filed Sept. 6, 1951 H6fm/en/or Geoffrey Cuff/s By his af/omeys Patented Apr. 6, 1954 BOBBINGeoffrey Curtis, Coventry, England, assignor to Courtaulds Limited,London, England, a British company Application September 6, 1951, SerialNo. 245,411

Claims priority, application Great Britain September 28, 1950 3 Claims.

This invention relates to metal bobbins.

In the production of dry-spun cellulose acetate threads, it is standardpractice to collect the threads directly on bobbins by means of twistingdevices, usually of the cap or ring type. The low degree of twist soinserted is usually suflicient for weaving and knitting purposes.However, when low denier threads, that is to say threads having a denierof the order of 80 or less, are collected in this manner there is atendency for individual filaments to separate and even to break and itis therefore customary in commercial weaving and knitting practice torewind these threads on to cheeses while increasing the degree of twist,thereby adding to the cost of the knitted or woven fabric.

The object of the present invention is to provide a metal bobbin for theoriginal collecting of packages of low denier, low twist threadssuitable for use directly in weaving and knitting processes.

A bobbin according to this invention consists of a metal shell havingthe shape and dimensions as defined below and, at the top of the bobbin,a smooth collar constructed for example from a phenol-formaldehyderesin, which provides a rubbing surface for the thread drawn off fromthe bobbin. The top part of the bobbin may also be splayed so that, withthe collar also functioning as an upper flange, the amount of yarn thatcan be wound on the bobbin may be further increased.

The yarn packages collected on the bobbin according to the invention aresuitable for use directly in warping, beaming and like operations usingcreels. In order to facilitate mounting of the bobbins on the creel, theedges of the lower flange are preferably turned under.

The bobbins according to the invention are preferably made of aluminum,which may be anodised to increase its surface hardness.

Bobbins constructed in accordance with the invention are illustrated inthe accompanying drawings in which Figure 1 is a vertical sectionthrough one type of bobbin,

Figure 2 is a vertical section through a further type of bobbin, and

Figure '3 is a section of the lower part of a modified form of bobbin ofthe type shown in Figure 2.

According to the present invention, the new bobbin for low deniercellulose acetate threads has a yarn-carrying surface between 7 and 10inches long and it is formed of a metal shell which is splayed in thevicinity of its lower end.

The shell has an integral lower flange, the minimum diameter of theshell being from 1% to 3 /2 inches and the ratio of the length of thesplayed portion to the total length of the yarnc-arrying surface beingin the range of 0.2 to 0.4: 1. The splayed portion of the bobbin maymerge directly into the lower flange or it may end just before theflange so that there is a narrow cylindrical portion between the splayedportion and the flange.

The bobbin shown in Figure 1 comprises a metal shell I having an uppersplayed portion 2, a cylindrical central portion 3, a lower splayedportion l and a short cylindrical portion 5 merging into a flange 6, thelower edge of which is turned under as shown. A phenol-formaldehyderesin collar 7 is fitted at the top of the bobbin to provide a rubbingsurface for the thread and to form a top flange. A yarn package 8 with asingle tapered end is preferably laid on the bobbin by means of atraverse mechanism with a hydraulic drive in which the shape of thepackage is determined by varying the rate of feed of fluid as describedin British patent specification No. 626,177.

One specific bobbin constructed as shown in Figure 1 has the followingdimensions:

Inches Overall length of bobbin 9 Length of yarn supporting surface 8Thickness of lower flange 6 /2 Diameter of bobbin at top 3% Diameter ofcentral cylindrical portion 2% Length of top splayed portion 2 1 /2 yLength of cylindrical portion 3 3 /2 Length of lower splayed portion 3 2/2 Maximum diameter of lower splayed portion 4 3% Width of lower flangeDiameter of cylindrical portion 5 3% Length of cylindrical portion 5 /2Diameter of resin collar 1 3% Ratio of length of splayed portion tototal length=from 0.2 to 0.411.

This bobbin is suitable for collecting 2 lb. packages of 55 deniercellulose acetate yarn.

The bobbin is preferably driven by means of a driving spindle asdescribed in U. S. patent application Serial No. 245,4 2, filed of evendate herewith.

The bobbin shown in Figure 2 comprises a metal shell 9 having an uppercylindrical portion I0, a lower splayed portion H and a shortcylindrical portion l2 merging into a flange l3 which is turned under asshown. A phenol-form- Inches Overall length of bobbin 9% Length of yarnsupporting surface 8% Thickness of lower flange l3 V2 Diameter ofcylindrical portion l'0 3 Length of cylindrical portion In 6%. Length oflower splayed portion tl Maximum diameter of lower splayed portion I l3% Width of lower flange I3 /2 Diameter of cylindrical portion 12 3%Length of cylindrical portion [2; /2 Diameter of resin collar [4 3%Ratio of length of spla e port-1.0mm total 1ength=fr0 ()2 to GAIL Thisbobbin is suitable for collecting 3 lb. packages of 55 denier celluloseacetate yarn.

Referring to Figure 3, the bobbin is substantially the same as shown inFigure 2 except that the lower flange I3 is extended to permit buildingup heavier packages and a metal ring [6 is inserted within the flange tostrengthen it.

What I claim is:

1. A bobbin for low denier cellulose acetate threads consisting of ahollow metal shell of substantially uniform thickness having ayarncarrying surface between 7 and 10 inches long, said shell beingsplayed in the vicinity of its lower end and having an integralyarn-supporting lower flange extending outwardly from the shell near thelarge end of the splayed portion, the minimum diameter of the shellbeing from 1% to 3 inches and the ratio of the length of the splayedportion to the total length of the yarn-carrying surface being in therange of 0.2 to 0.4:1, in combination with a smooth collar fitted to thetop of the shell to provide a rubbing surface for thread drawn off thebobbin; whereby adequate strength is combined with sufiicientyarn-carrying space.

2. A bobbin for low denier cellulose acetate threads consisting of ahollow metal shell of substantially uniform thickness having ayarncarrying surface between 7 and 10 inches long, said shell beingsplayed in the vicinity of its lower end and having an integralyarn-supporting lower flange extending outwardly from the shell, thesplayed portion of the shell being separated from the flange by a narrowcylindrical portion, the minimum diameter of the shell being from 1% to3 inches and the ratio of the length of the splayed portion to the totallength of the yarn-carrying surface being in the range of 0.2 to 0.4:1,in combination with a smooth collar fitted to the top of the shell toprovide a rubbing surface for thread drawn off the bobbin; wherebyadequate strength is combined with sufficient yarn-carrying space.

3. A bobbin as claimed in claim 2 wherein the top part of the shell isalso splayed, the top and bottom splayed portions of the shell beingseparated by a cylindrical portion.

